Aquaticus: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species. 

	plants NOT alpine
	plants NOT rhizomatous
	leaves cuneate, rounded, truncate or cordate at base;  NOT [leaves hastate or sagittate]
	pedicels obscurely jointed; NOT [pedicles conspicuously jointed]
	flowers perfect or mostly so; NOT [flowers unisexual]
	valves not greatly enlarging; NOT [valves greatly enlarging in fruit, becoming bright pink]
	valves smaller; NOT [valves 1-3 cm across]
	valves entire or nearly so; NOT [valves distinctly lobed or toothed on the margin]
	valves without tubercles; NOT [tubercles 1-3, well-developed]

Rumex: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. 

	NOT [dwarf annual; leaves subopposite; calyx 3-parted; stamens 3]
	leaves with stipules
	leaves lanceolate; NOT [leaves reniform]
	flowers not in involucrate clusters; NOT [flower clusters subtended by an involucre of bracts]
	stamens 8 or fewer; NOT [stamens 9]
	stigmas tufted
	sepals 6; NOT [sepals 4], NOT [sepals 5, more or less equal]
	inner sepals enclosing the fruit; NOT [inner sepals erect]
	fruit winged; NOT [fruit wingless]

Polygonaceae: Answers to key questions in Budd's Flora  leading to this family. 

	herbs; NOT [shrubs or trees]
	land plants; NOT [water plants]
	plants not parasitic on trees, rooted in soil or water; NOT [plants parasitic on branches of trees]
	plants with stems or stemless, but with more than one pair of leaves; NOT [plants stemless with a single pair of large reniform leaves, calyx 3-lobed]
	leaves alternate; NOT [leaves opposite]
	stipules forming a sheath above nodes; NOT [stipules membranous], NOT [leaves without stipules]
	flowers with only one floral ring, with sepals but not petals
	stamens and pistils in each flower; NOT [stamens or pistils in separate flowers on the same plant]